Road binder and surface coating from coal



COMPRESSIVE STRENGTH PSI Sept. 12, 1967 H. H. GINSBERG ETAL ROAD BINDERAND SURFACE COATING FROM COAL Filed March 2, 1965 IOOO- :2: 200- E g I50O 0*. 0. 20 O oilo 0:20

DEFORMATION INCHES DEFORMATION INCHES F/G'J F761? E 250- 200- i 5 I50- 5I00 8 50 DEFORMATION' INCHES INl/E/VTORS F HENRY H. GINSBERG 3 MART/IV0. scams/mm RAYMOND W H/TESHUE A TTOR/VEYS United States Patent Ofiiice3,341,344 ROAD BINDER AND SURFACE COATING FROM COAL Henry H. Ginsberg,Martin D. Schlesinger, and Raymond W. Hiteshue, Pittsburgh, Pa.,assignors to the United States of America as represented by theSecretary of the Interior Filed Mar. 2, 1965, Ser. No. 436,699 4 Claims.(Cl. 106281) ABSTRACT OF THE DISCLOSURE A paving composition composed ofan aggregate and an asphaltene binder derived from a coal hydrogenationprocess.

The invention herein described and claimed may be manufactured and usedfor or by the Government of the United States of America forgovernmental purposes without the payment of royalties thereon ortherefor.

This invention relates to the use of coal-hydrogenation asphaltene as abinder for paving and construction materials.

FIGS. 1, 2 and 3 are graphs of compressive strength versus distortion ofbriquets prepared according to applicants invention (FIG. 1) and priorart briquets (FIGS. 2 and 3).

Various types of asphaltenes have been used as ingredients in bindingcompositions for roofing or paving and for lining pipes, conduits, etc.,and in coating compositions. Such compositions have, however, generallyfailed to provide the compressive strength required for a high qualitypaving material.

It has now been found that the use of a particular asphaltene, thatobtained from coal hydrogenation, as a binder results in a producthaving desirably high compressive strength, as well as resistance tosolvent action of petroleum products such as jet fuels. These propertiesare of particular value when the products are used for construction ofair port runways or where automotive vehicles stand for periods of time.In these areas jet fuel and gasoline drippings and spillage can attackpetroleum asphalt binders and cause serious damage.

The paving and construction materials of the invention comprise anaggregate, such as limestone or slag, and asphaltene derived from coalhydrogenation. The asphaltene is prepared according to the followingdescription.

Conversion of coal into liquid fuels by the hydrogenation processconsists of adding hydrogen to the coal at elevated temperatures andpressures in the presence of a catalyst. A two-step operation isemployed in the production of gasoline. In the first or liqueficationstage, the coal and the oil in which the coal was suspended areconverted to a product which includes a broad range of hydrocarbon andoxygenated compounds from low-boiling to undistillable oils. The heavyfractions are recycled with fresh coal. The lighter and middle oilsboiling up to about 325 C. are used as feed for the second orvapor-phase step. In this second step the distillable oils are convertedto gasoline or other specification fuels.

The asphaltene of the invention is recovered by solvent extraction withbenzene and n-hexane from the nondistillable oils from the liqueficationstep of the process. The heavy oil is first treated with sufiicientbenzene to remove all the soluble oil, leaving as a residue insolublecoal- ]ike material and ash. Most of the benzene is then recovered bydistillation. The oil residue is then treated with nhexane and a heavytarry-like precipitate, asphaltene, is formed. The n-hexane is removedby filtration and heating and the asphaltene is used with aggregate inthe preparation of the products of the invention. An alternative methodwould be to produce a product consisting mostly of asphaltenes andunreacted coal by the hydrogenation of coal at short residence times.The asphaltenes plus unreacted coal would not be separated but would bemixed, as is, with limestone.

Properties of the asphaltene are given in Table 1, along withcorresponding properties of petroleum asphalt, conventionally used as ation compositions.

TABLE 1.-ANALYSES OF ASPHALT AND ASPHALTENE M Air blown Asphaltenepetroleum from hydroasphalt from a genation of midcontinent RockSprings, crude, wt. pct. Wyo. coal, wt.

' pct.

Moisture 0. 00 Trace Ash 0.02 0.85 Ultimate (mat):

H 10. 7 6. 3 87. 5 91. 6 0.6 1.7 S 0.8 0. 1 O (by difference) 0.4 0.3Benzene ins0luble. 0. 13 2. 8 Asphaltene 20.0 69. 6 Differenceasphaltene 1 15.1 34.8 Difference resins 1 4. 8 34. 8 Resins 59. 1 19. 3Oils 20. 2 21. 2 Solubility in CC 9997 Solubility in OS 99.95 Softeningpoint; (R and B) F 114.0 110.0 Distillables to:

300 C 0. 0(1 1.24 355 C 0.52 2. 66 Penetration at 77 F., mm. l0 72. (1119.0

Difierence asphaltenes and Difierence resins are solvent separatediractions of asphaltene. Difference asphaltenes are soluble in benzenebut insoluble in ethyl ether.

Although limestone is the preferred aggregate used in preparation of theproducts of the invention, other maters such as slag or gravel may beused. The particle size and amount of the aggregate are not critical andwill vary considerably depending on the particular use of the product.Generally, the particle size will vary from about /s in. to No. 10 US.sieve size and the amount of aggregate will be about to percent byweight of the composition.

The aggregate, such as limetones, is dispersed in the asphaltene byheating to a suitable temperature and mixing the two ingredients.Application of heat, usually about C., is necessary to maintain theasphaltene at a viscosity suitable for mixing.

Although the two-component mixture of aggregate and asphaltene has beenfound to give very good results, other materials, such as theconventional binders petroleum asphalt or tar, may also be included inthe composition. Mixtures of diiferent types of aggregates may, ofcourse, also be employed.

The following example will serve to more particularly describe theinvention.

Example I Briquets prepared from limestone and coal-hydrogenationasphaltene were compared with similar briquets prepared from limestoneand petroleum asphalt (penetration grade 85-100) or high temperaturecoke-oven tar. Analysis of the asphaltene and asphalt are those given inTable l. Cylindrical briquets 4 inches in diameter and 4 inches inheight were prepared, by moulding, from limestone aggregate andcoal-hydrogenation asphaltene, petroleum asphalt or coke-oven tar asbinder. The limestone aggregate had a particle size of 50% to Main. and50% A in. to No. 10 sieve size and comprised 90 percent by weight of thecomposition. Binder and aggregate were heated sep- Patented Sept. 12,1967- binder in paving or other construcarately to about 165 C. (about110 C. when tar was used as binder). The heated materials were thencombined and mixed for about 2 minutes so that the aggregate was allcoated by the binder. The mixture was then poured into a mold and spadedto eliminate void spaces. Molding was done at 125 C. for asphaltene andasphalt and at 105 C. for tar, under a compressive stress of 3000'p.s.i. held for 2 minutes. The specimens were then removed from themold, oven cured at 60 C. for 24 hours and then cooled to roomtemperature in a desiccator.

The briquets were tested according to ASTM method D1074-58T in which anaxial stress is applied to the briquet which is unsupported laterally.The stress is applied so as to obtain a uniform rate of verticaldeformation, until complete failure occurs. Results are shown in FIGURE1 for coal-hydrogenation asphaltene, FIGURE 2 for petroleum asphalt andFIGURE 3 for coke-oven tar. Superiority of the coal-hydrogenationasphaltene is evident: the maximum compressive strength for thecoalhydrogenation asphaltene product is about 1800 p.s.i. whereas thatof the coke-oven tar products was 425 p.s.i. and that of the petroleumasphalt product only 250 p.s.i.

In addition, after the maximum strength of the coal-hydrogenationasphaltene briquet was reached, it did not crumble as did the briquetsmade with petroleum asphalt. Resistance of the coal-hydrogenationasphaltene briquets to solve action of hydrocarbons was shown bynegligible weight loss when they were immersed in ]P4 jet fuel at roomtemperature for 24 hours; results are shown in Table 2.

TABLE 2 Loss in wt. of Briquets: of binder, percent Petroleum asphalt 8Coke-oven tar 3 Coal hydrogenation asphaltene 1 Although the propertiesof the composition of the invention make it of particular value forconstruction of airport runways, it is also of value for a variety ofother uses such as road building, construction of moisture barriers,preparation of water-resistant surface coatings, etc.

What is claimed is:

1. A paving and construction composition consisting of a mixture of anaggregate and a binder consisting of asphaltene derived fromhydrogenation of coal.

2. Composition of claim 1 in which the aggregate is limestone.

3. Composition of claim 2 in limestone in the composition is by weight.

4. Composition of claim derived by (a) contacting nondistillable heavyoils from said coal hydrogenation process with benzene to extract oilfrom said heavy oils;

(b) separating said benzene from said extracted oil;

which the proportion of from to percent 1 wherein said aspahltene is (c)contacting said extracted oil with n-hexane to precipitate saidasphaltene therefrom; and (d) separating out said asphaltene.

References Cited UNITED STATES PATENTS 2,366,657 1/1945 Sorem 106-273 XR2,658,026 11/1953 MacLaren et al. 106-273 XR 2,673,814 3/1954 MacLaren106-273 XR 2,913,389 11/1959 Heithaus 94-20 XR 3,074,807 1/1963 Doriuset al. 106-273 ALEXANDER H. BRODMERKEL, Primary Examiner. I. B. EVANS,Assistant Examiner.

1. A PAVING AND CONSTRUCTION COMPOSITION CONSISTING OF A MIXTURE OF ANAGGREGATE AND A BINDER CONSISTING OF ASPHALTENE DERIVED FROMHYDROGENATION OF COAL.